RU2336280C2 - Improved method of processing vegetable material, containing pectin - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to pectin and processed initial material, which contains pectin. Method of obtaining processed initial material by deactivation of pectinesterase includes obtaining fruit vegetable material, containing pectin, and bringing it in contact with water, which has pH value from 3.2 to 3.9, at temperature ≤70°C. After that processed initial material is extracted. In addition, invention relates to use of processed initial material, containing pectin, obtained according to said method, respectively, for pectin extraction, as food for animals or as ingredient in food products. In addition invention relates to pectin, obtained according to said method, by means of extraction from initial vegetable material, molecular weight of said pectin being higher on value up to 50% than molecular weight of pectin, obtained from extraction of similar but unprocessed initial vegetable material, containing pectin. Ratio of sensitivity to calcium of said pectin and sensitivity to calcium of pectin, extracted from similar, but unprocessed with washing, initial vegetable material, which contains pectin, is within 0.90-1.40. Pectin preserves molecular weight and etherification degree well, has high output and low sensitivity to calcium.

EFFECT: obtaining method of processing vegetable material, which contains pectin, preserving molecular weight and degree of pectin etherification.

30 cl, 2 dwg, 19 tbl, 9 ex

Description

FIELD OF THE INVENTION

The present invention relates to an improved method for processing pectin-containing starting material to reduce or prevent chemical and / or enzymatic and / or microbiological changes in pectin contained in said pectin-containing starting material.

BACKGROUND AND RELATED INFORMATION

Pectin is a complex polysaccharide associated with plant cell walls. It consists of the main chain of alpha 1-4 linked polygalacturonic acid interrupted by ramnose residues, and with side chains modified with neutral sugars and components other than sugars, such as acetyl, methyl groups and ferulic acid groups.

The side chains of neutral sugars, which include arabinan and arabinogalactans, are attached to the ramnose residues in the main chain. Rhamnose residues tend to come together on the main chain. Thus, the side chains attached to this region are referred to as a fleecy region, and the remainder of the main chain is therefore referred to as a smooth region.

In US patent 5929051, Ni, et al. pectin is described as a component of plant cell walls. The cell wall is divided into three layers: the median plate, the primary and secondary cell wall. The middle plate is the richest pectin. Pectins are produced and precipitated during cell wall growth. Pectin is especially abundant in the soft tissues of plants, under conditions of rapid growth and high moisture content. In the cell walls, pectins are present in the form of a calcium complex. The presence of cross-linking with calcium is proved by the fact that chelating agents facilitate the release of pectin from cell walls, as described by Nanji (US Pat. No. 1,634,879) and Maclay (US Pat. No. 2,375,376).

According to Dumitriu, S .: Polysaccharides, Structural diversity and functional versatility, Marcel Dekker, Inc., New York, 1998, 416-419, pectin is used in a variety of food products.

Historically, pectin has been used primarily as a gelling agent for jam or the like containing sugar or fruit rich fruit or fruit flavors. Examples are traditional jams, low-sugar jams, clear jellies, fruit flavored confectionery jellies, fruit flavored confectionery jellies, thermally reversible frosting for the bakery industry, heat-resistant jams for the bakery industry, curl-shaped slices for use in ice cream and fruit semi-finished products for yogurt.

A significant portion of pectin is used today to stabilize low pH dairy drinks, including fermented drinks and mixtures of fruit juice and milk.

Residues of galacturonic acid in pectin are partially esterified and present as methyl ester. The degree of esterification is defined as the percentage of esterified carboxyl groups. Pectin with an esterification degree ("DE") above 50% is referred to as high methyl ester ("HM") pectin or a high esterification pectin, and pectin with a DE lower than 50% is referred to as low pectin methyl ester ("LM") or pectin with a low degree of esterification. Most of the pectin found in plant material, such as fruits, vegetables, and zosters, is HM pectins. Acetate ester groups may also be present on the carbon atom of 2 or 3 residues of galacturonic acid. The degree of acetate esterification (“DAc”) is defined as the percentage of galacturonic acid residues containing an acetate ester group. Most natural pectins have low DAc, the only exception being sugar beet pectin.

Pectins are soluble in water and insoluble in most organic solvents. Pectins with a very low level of methyl esterification and pectic acids are soluble for practical purposes only in the form of potassium or sodium salts.

Pectins are most stable at pH 3-4. At pH below 3, the methoxyl and acetyl groups and side chains of neutral sugars are removed. At elevated temperatures, these reactions are accelerated, and glycosidic bonds are cleaved in the galacturonan backbone. Under neutral and alkaline conditions, methyl ester groups are saponified, and the polygalacturonan backbone is destroyed by beta-elimination-cleavage of glycosidic bonds at the non-reducing ends of methoxylated galacturonic acid residues. Also, these interactions occur faster with increasing temperature. Pectic acids and LM pectins are resistant to neutral and alkaline conditions, since methyl ester groups are absent or are present only in limited quantities.

According to Kertesz, Z. I: The Pectic Substances, Interscience Publishers, Inc, New York, 1951, pectin materials are found in all plant tissues. However, apples, beets, flax, grapefruit, lemons, limes, oranges, potatoes and sunflowers are of particular industrial importance. Later, the industrial importance of pectin in Aloe vera was also demonstrated.

In US Pat. No. 1,513,615, Leo describes an enzymatic method for solubilizing protopectin. He observes that pectase does not work when acid is present. As a result, it destroys fruit cells by cooking in water, and then it adds calcium carbonate, after which it adds pectase. Thus, Leo increases the pH to the point at which pectase becomes active, to prevent the use of acid in the next subsequent extraction.

In US Pat. No. 1,497,884, Jameson finds a solution to the problem that the peel contains pectinase, which removes methyl groups on pectin. When pectinase is present, pectin loses methyl groups, and this leads to a lower ability to form a gel. It solves the problem by grinding, first the peel, and then breaking down the pectinase by heating the crushed peel to a temperature just below 100 ° C, for no more than 10 minutes.

In US Pat. No. 1,654,131, Leo deactivates enzymes in the peel by treating the peel, cut into slices or slices, with a strong alcohol such as 95% ethanol. Thus, it solves the problem of reducing the ability of pectin to form a gel when the peel is dried in the presence of acids and enzymes. Leo takes advantage of the fact that alcohol denatures proteins such as enzymes, but it does not use any effect on the enzymes by lowering the pH.

In US Pat. No. 2,020,572, Platt uses the same principle as in US Pat. No. 1,497,884, and treats the finely ground peel with heat to break down the enzymes.

In US Pat. No. 2,165,902, Myers solves the problem that conventional oven drying of the peel does not heat the peel quickly enough to deactivate the enzymes. He does this by leaching the crushed fresh peel with a solution of copper sulfate heated sufficiently to deactivate pectinase.

In US Pat. No. 2,323,483, Myers deactivates enzymes in fresh peels by washing the shredded fresh peels in water at 90 ° C. for 5 minutes.

In US Pat. No. 2,358,430, Willaman describes a method for enzymatically deesterifying pectin. It processes the dispersion of pectin with pectase, at pH 6.0 and at a temperature that is favorable for pectase. This temperature is 40-45 ° C, and after a certain time during which the pH is maintained at 6.0, the reaction is stopped by heating to 70-80 ° C or by lowering the pH to 3-4, and then heating. Willaman notes a solution to the problem that conventional methods for deesterification of pectin, i.e., at that time, alkaline deesterification, lead to a decrease in the gel-forming ability of the obtained deesterified pectin. He does this by allowing the pectase enzyme to de-ester pectin.

In US Pat. No. 2,444,266, Owens describes a method for producing a series of partially demethoxylated high molecular weight pectins by allowing a natural enzyme to interact on citrus peel or apple pomace prior to extraction. He emphasizes that the peel should not be processed to inactivate the enzyme.

In US Pat. No. 2,387,635, Bailey describes a method for preparing pectin-containing plant material for extraction of pectin. The method includes removing soluble solids before extraction. The method includes the steps of adjusting the pH to 2.8-3.5, heating the source material to about 90 ° C for about 10 minutes, cooling the material to about 37-40 ° C, adding and growing yeast in it, thereby destroying pectin-free carbohydrate substances, bringing the pH of the fermented mass to about 2.9, and heating and subsequent extraction of pectin. Initial heating deactivates any enzymes and microorganisms present. Fermentation removes sugars and other unwanted soluble solids.

GB 4,53877 describes a procedure for processing plant material containing pectin. Plant material before extraction of pectin is treated with an organic or inorganic acid, without impairing the gelling ability of pectin. The procedure leads to a change in the gel-forming ability of the obtained pectin. During processing, the pH is maintained at 0.1-2.5.

US Pat. No. 5,567,462 describes a procedure for preparing a pectin cellulose composition, wherein the crushed citrus peel or other material containing pectin is treated with an acidified aqueous solution to solubilize the pectin. US patent 5567462 proposes the use of acids, leading to a pH in the range from 1 to 3.3, for the solubilization of pectin.

Japanese patent JP 59-096105 describes a procedure for producing high quality pectin in good yields. In this method, a solution of a mineral acid of at least 0.01 N. (i.e., with a pH of about 0.3-2) is described as a limit to the solubilization of pectin.

Japanese Patent JP 61-085402 describes a process for producing high quality pectin in high yields by contacting a dry plant material containing pectin with an acid, at a temperature below 10 ° C., before extraction. The described acids are inorganic acids with a strength of 0.5-5.0 N. (i.e., with a pH of about 0.1-0.3).

In summary, prior art deals with enzyme problems in the skin. However, these enzymes are seen as a problem, not an opportunity. Thus, for the most part, natural enzymes are destroyed by the use of heat. In fact, the state of the art claims that conventional drying in an oven is insufficient to break down an enzyme, and as a consequence, preheating in an aqueous system is necessary. Another approach involves using ethanol to break down enzymes before drying the peel. This method, however, is dangerous due to the potential risk of explosion.

The use of natural enzymes for the deesterification of pectin in the peel is known. However, this principle is either used on pectin, which is extracted, or this principle is used on fresh peel.

As a consequence, there is a need to prepare a dry starting material containing pectin, in which the natural enzymes are made deactivated, so that they do not alter the composition of the pectin in the fresh skin during transport and during drying. In addition, enzymes must be deactivated in a dry skin during storage. However, when the dry peel is to be extracted, the enzymes must again become active, so that in situ deesterification in the peel can be achieved before pectin extraction.

SUMMARY OF THE INVENTION

It has now been unexpectedly discovered that when the pH in a fresh peel is brought to a value in the range of 3.2 to 3.9, at a temperature below 90 ° C., the natural pectin esterase in the peel becomes deactivated. Thus, there is minimal deesterification during the transportation of fresh peel and during subsequent washing and / or normal drying of fresh peel. Since the enzyme remains deactivated, the activity of the enzyme can be restored at a later point in time, by increasing the pH to a value higher than about 4.0.

The present invention includes a method for processing such plant material resulting from pectin, the claimed invention allows to achieve an unexpectedly high degree of conservation of molecular weight of pectin, a high degree of conservation of the degree of esterification, high yield of pectin and its low sensitivity to calcium, which could not be predicted based on prior art.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an improved method for processing pectin-containing plant starting material before extracting pectin from a pectin-containing plant starting material.

Pectin-containing plant material may be any pectin-containing material. Such materials include citrus fruits, other fruits such as apples, beets, soy protein production residues, flaxseed or onion, scarlet, sunflower hats, and the like. The present invention is particularly suitable for treating a plant starting material containing pectin that initially has a pH above 4. Examples of such plant materials are orange, grapefruit, fodder beets, sugar beets and carrots.

The present invention includes a method for processing such plant material resulting from pectin obtained by subsequent extraction of the processed starting plant material containing pectin and using said pectin.

The method includes the following stages: As quickly as possible, after physical manipulations with the starting plant material containing pectin, for example, squeezing, the residues, for example, citrus peel, seeds and squeezes after receiving the juice, are treated with acidified water. If this is difficult, processing of the plant starting material containing pectin should take place as quickly as possible after washing with fresh water the plant starting material containing pectin. Pectin-containing plant material may be processed as it is received, or pectin-containing plant material may be ground or chopped to improve processing. The pH of acidified water can vary from 3.2 to 3.9, and more preferably, from pH 3.4-3.7. At pH values below about 3.2, pectin will be solubilized, which is undesirable. At pH values of about 4 and above, on the other hand, natural pectin esterase becomes active and begins to deesterify and degrade pectin. The treatment with acidified water or washing with acidified water can be carried out in boot mode or in continuous mode. In the boot flushing method, one or more washing steps can be used to remove as much soluble material such as sugar as possible. Although more than three washing steps can be used to remove even more solutes, the three washing steps give an acceptable level of solute without an unacceptable cost increase. In a continuous washing method, acid is added at the end of the washing line, where the natural acids, if present in the plant material containing pectin, have the lowest concentration. Such continuous countercurrent flushing technologies are well known in the art.

The acid used in the present invention can be any inorganic or any organic acid capable of lowering the pH of the starting plant material containing pectin to the desired pH. Examples of inorganic acids include hydrochloric acid, sulfuric acid, sulfur dioxide, nitric acid and the like, and examples of organic acid include citric acid, oxalic acid, acetic acid and the like. Other means to achieve the desired pH of the starting plant material containing pectin are by using a buffer solution instead of an acid. Examples of buffer solutions include:

Chemicals Usable pH range of the buffer solution at 25 ° C Hydrochloric Acid / Disodium Hydrocytrate 2.0-4.0 Glycine / hydrochloric acid 2.2-3.6 Potassium Hydrophthalate / Hydrochloric Acid 2.2-4.0 Citric Acid / Sodium Citrate 3.0-6.2 Sodium Acetate / Acetic Acid 3.7-5.6

To prevent the extraction of pectin contained in the plant starting material containing pectin, washing with acidified water should take place at temperatures below 90 ° C, preferably below 50 ° C, and most preferably below 35 ° C. For practical purposes, washing with acidified water should take place at a temperature of water acceptable to the touch, which in most cases should be between 10 ° C and 30 ° C, but lower temperatures of acidified water can also be used.

When a loading washing method is used, it is convenient to slightly squeeze the washed pectin-containing plant material between subsequent washes in order to ensure the best possible removal of solutes. The extraction should be carried out in such a way that the starting plant material containing pectin is only wrung out to release excess liquid, but not in a way that causes crushing of the starting plant material containing pectin so that it is not difficult to separate and / or dry further in the method.

The time during which the pectin-containing plant material is washed with acidified water should be sufficient to effectively reduce the pH of the pectin-containing plant material to a pH in the range of 3.2 to 3.9, and more preferably in pH range from 3.4 to 3.7. This time is usually in the range of 5-60 minutes for each washing step, preferably 5-30 minutes for each washing step, and most preferably 10-20 minutes for each washing step. Longer flushing times are possible but do not provide any additional benefits.

After washing with acidified water, the activity of plant esterase in the treated starting plant material containing pectin is inactive or deactivated. Thus, plant esterase, which is present in nature, in the plant material containing pectin no longer produces its effect of deesterification on the pectin contained in the plant source material containing pectin. Thus, the treated pectin containing plant starting material can be stored or transported without deesterifying the pectin contained in the pectin containing plant starting material. This is important because plant esterase deesterifies pectin in a pectin containing plant material in a block manner, which makes the resulting pectin more sensitive to calcium. In addition, by preventing the formation of carboxylic acid group blocks, the risk of depolymerization during subsequent drying and extraction at high temperatures is minimized. By deactivating plant esterase, pectin remains unchanged. Pectin in the processed pectin containing plant starting material may subsequently be extracted in accordance with known methods.

The treated pectin containing plant starting material may also be used for direct extraction in accordance with known methods. Alternatively, the treated pectin-containing plant starting material may be dried and optionally ground prior to extracting pectin from the dried pectin-containing processed plant source. This feature is especially useful when the processing operation and the extraction operation are far apart and when transporting the wet treated peel is impractical. The present invention is particularly useful when the treated plant material containing pectin is subsequently dried. Drying can take place by any known method, with or without vacuum. A drying temperature lower than 80 ° C is recommended to prevent the formation of a hard coating on the surface of the plant starting material containing pectin. Since plant esterase can be deactivated and remains deactivated during the drying step, the disadvantage of known drying principles of the starting plant material containing pectin is eliminated. During conventional drying, in which plant esterase is not deactivated, slow heating during drying leads to severe deesterification, which is prevented by the present invention.

However, the present invention also enables the reactivation of plant esterase so that block deesterification can occur in wet or dry, acid washed raw plant material containing pectin prior to extraction. This is accomplished by spraying a wet or dry acid-washed pectin-containing plant material with an alkali solution such as dilute sodium hydroxide or any other suitable alkali to adjust the pH of the pectin-containing plant material to a value in excess of 4.0 preferably up to 4.5-6.0, and most preferably up to 4.5-5.5. Alternatively, a wet or dry, acid-washed pectin containing plant starting material may be suspended in said diluted alkali. The temperature is selected as the optimum temperature for plant esterase, which is in the range of 40-80 ° C, preferably 50-70 ° C, and most preferably 60-70 ° C, and the time is selected to achieve the desired block deesterification. Depending on the temperature, the time ranges from about 1 hour, at high temperatures, to several hours, at lower temperatures.

The present invention also relates to pectin extracted from processed pectin containing plant starting material. Thus, treatment of a plant material containing pectin in accordance with the present invention results in pectin with low calcium sensitivity. In fact, the sensitivity to calcium, when measured as the ratio of the tensile strength between the gel obtained with the addition of calcium ions, and the gel obtained without the addition of calcium ions, is in the range from 0.90 to 1.40, preferably from 0.90 to 1.20, and most preferably from 0.90 to 1.10. This improvement in calcium sensitivity is especially beneficial for pectin derived from orange, grapefruit, and beets.

In addition, said pectin has a higher molecular weight than pectin which is not subjected to the processing of the present invention. Molecular mass increases by up to 50%, often by 10-40%, and usually by 15-30%. The increase in molecular weight is especially pronounced when using orange, grapefruit and beets.

In addition, the traditional USA SAG (see below for definitions) of pectin is increasing. By treating pectin-containing plant material in accordance with the present invention, the USA SAG is increased by up to 30%, more often by 5-25%, and usually by 10-20%. The increase in USA SAG is especially pronounced when using orange, grapefruit and beets.

The present invention also relates to the use of processed pectin containing plant material in the production of pectin, in the manufacture of animal feed and for use in food products.

The present invention also relates to uses of said pectin. Applications include food products, cosmetic products, pharmaceutical products, and household products. The pectin of the present invention is particularly suitable for the preparation of jams and jellies, for baked goods containing jams and dough, either layered or not, acidified protein drinks, wound care products, products for stoma patients , and the like.

Materials and methods

• Pectin Extraction

In the present application, pectin is extracted using the following steps:

1. 15 liters of water are heated to 70 ° C in a container with a stainless steel casing having a volume of 18 liters and equipped with a stirrer.

2. 500 g of the peel is added to water and the pH is adjusted to 1.7-1.8 by adding 62% nitric acid.

3. The extraction is carried out at 70 ° C, for 7 hours, with stirring.

4. After extraction, the contents of the container are filtered in a Buchner funnel using diatomaceous earth as a filter medium.

5. The filtered extract is subjected to ion exchange, with stirring, by adding 50 ml of resin (Amberlite SR1L, manufactured by Rohm & Haas) per liter of filtered extract. During stirring, ion exchange is carried out for 20 minutes, with stirring.

6. The ion-exchanged filtrate is filtered on a Buchner funnel equipped with a cloth.

7. The filtered, ion-exchanged filtrate is precipitated by adding it to three parts of 80% isopropanol, while stirring gently.

8. The precipitate is collected on nylon fabric and manually squeezed to remove isopropanol as much as possible.

9. The manually squeezed precipitate is washed once in 60% isopropanol and then dried at 70 ° C in an oven at atmospheric pressure.

10. After drying, the pectin is crushed.

• Tensile strength and IPPA temperature at SS 65% for HM pectin (slow procedure)

Principle

The tensile strength is measured on a Texture Analyzer (TA-XT2) in synthetic jelly, at 65% and pH 3.0. Tear strength is measured at a calcium level of 0 ppm. Ca ²⁺ (rupture-Ca ²⁺ ) and 90 ppm Ca ²⁺ (gap + Ca ²⁺ ).

Equipment:

1. Scales (maximum load 3-6 kg)

2. Glass beakers, (1000 ml), 2 pieces

3. Volumetric flask, (1000 ml), 2 pieces

4. Magnetic stirrer

5. High speed mixer

6. Electric warm table, diameter 15 cm, 1500 W

7. Saucepan, stainless steel, 1.5 L

8. Scoop

9. 500 rpm agitator

10. Spindle of a mixer (HETO, article No. 000240, drawing No. 0004259)

11. Pipette

12. Thermostatically controlled water bath Haake D-8-G

13. Steel containers for samples (inner diameter 50 mm, inner height 74 mm) with lids

14. Petri dishes (lower part), diameter: 61 mm, height: 9 mm

15. Lids for Petri dishes

16. Oven at 25 ° C ± 2 ° C

17. Adhesive tape

18. Wire cutting for cheese

19. Texture Analyzer, type TA-XT2

20. Refractometer

21. pH meter

22. Stopwatch

23. Windows computer

24. Printer

25. Computer program for determining the temperature of IPPA. This software is available from CPKelco.

Buffer solution No. 1 (+ Ca ²⁺ ): Potassium Monohydrate, K ₃ C ₅ H ₅ O ₇ , H ₂ O:
Calcium tetrahydrate citrate, Ca ₃ (C ₆ H ₅ O ₇ ) ₂ , 4H ₂ O:
Sodium benzoate, C ₇ H ₅ NaO ₂ :
Citric acid, monohydrate, C ₆ H ₈ O ₇ , H ₂ O,
50% (w / v): 3.933 g
1,898 g
1,000 g
25 ml (approximately)

Dissolve in the indicated sequence in 900 ml of deionized water, add citric acid, with stirring, until calcium citrate dissolves. The pH was adjusted to 3.4-3.5 with citric acid and transferred quantitatively to a 1000 ml volumetric flask, which was filled to the mark with deionized water.

Buffer solution No. 2 (-Ca ²⁺ ): Potassium citrate monohydrate, K ₃ C ₆ H ₅ O ₇ , H ₂ O:
Sodium benzoate, C ₅ H ₇ NaO ₂
Citric acid, monohydrate, C ₅ H ₈ O ₇ , H ₂ O,
50% (w / v): 3.933 g
1,000 g
18 ml (approximately) Dissolve as buffer solution No. 1. A solution of citric acid 50% wt./volume:
Citric acid, monohydrate, C ₆ H ₈ O ₇ , H ₂ O: 500 g

Dissolve citric acid in deionized water and supplement with deionized water to 1000 ml, in total.

Pectin solution: Boiling water, deionized:
Pectin (150 degrees USA-SAG): 380 ml
x g

Water is weighed and pectin is slowly added to the high-speed mixer at speed 1. After addition, the speed is increased to speed 3, over 5 minutes. Cool the solution to ambient temperature and increase the mass to 400 g, and mix in a high-speed mixer. Weigh out 121 g of pectin in a 250 ml glass beaker.

Calculation of x g pectin:

(8.7 x 150) / (assumed USA-SAG degree) = x g

Recipe:

Soluble solids%: 65.0 ± 0.5 pH: 3.0 ± 0.05

Gel + Ca ^2+:

Buffer solution No. 1: 135 g Sugar:
Pectin solution:
Citric acid solution, approximately
50% (w / v): 385 g
120 g
3 ml (estimated amount) In general, approximately: 643 g Evaporation, approximately:
Final output: 43 g
600 g

Gel -Ca ²⁺ :

Buffer solution No. 2: 135 g Sugar: 385 g Pectin solution: 120 g Citric acid solution, approximately
50% (w / v): 2.5 ml (estimated amount) In general, approximately: 642.5 g Evaporation, approximately: 42.5 g Final output: 600 g

Procedure:

Determination of IPPA temperature (developed by CP Kelco) and preparation of sample solutions with and without calcium:

1. Launch the program. Use the following settings:

• Initial temperature: 95 ° C

• Final temperature: 15 ° C

• Temperature gradient: 1 ° C / min

• Enter file name

2. Fill deionized water in a metal container and place in a thermostatically controlled Haake D-8-G water bath.

3. Place the reference sensor in the middle of the container and press START. After that, the water bath will be heated to the initial temperature.

4. Weigh the buffer solution in an enamel pan (diameter 16 cm, internal height 7.5 cm). Add sugar and start the stopwatch. Heated to boiling with stirring (500 rpm).

5. Pectin solution is added from a 250 ml glass beaker (120 g) and scraped out (residue in a beaker about 1 g), and boiling and stirring are continued.

6. Continue boiling for 1 minute.

7. Add the calculated amount of citric acid solution. Boiling and stirring are continued for 30 seconds.

8. Increase the mass to 600 g with deionized water or boil for evaporation. (In practice, a slightly larger amount of water may be added to achieve the correct dissolution of solid products).

9. Remove the pan from the heat and mix using a scoop. Leave for 20 seconds before removing all foam.

10. Fill two containers with samples (with covers) for the Haake D-8-G thermostatically controlled water bath and place the sensors in the middle of the containers. Press the green PRE TO GO ON button. After the temperature difference drops to less than 2 ° C, cooling starts. Finally, the computer will calculate the gelation temperature.

Determination of tensile strength:

1. Fill, immediately after stage 7, 3 Petri dishes (lower part) (diameter 61 mm, height 9 mm), they are all equipped with a shell of tape.

2. Cover the Petri dishes with lids to prevent the gel from drying out when standing.

3. Leave the jelly for 18-24 hours at 25 ° C ± 2 ° C before measuring the tensile strength.

Gap:

1. Remove the casing from the tape and cut off the upper parts of the jelly using wire cutting for cheese flush with the top edge of the Petri dish.

2. Measure tensile strength on TA-XT2

• Distance traveled by the plunger: 6 mm

• Plunger diameter: 12.7 mm

• Plunger speed: 0.5 mm / sec.

3. The results are obtained as average values for three jellies with Ca ²⁺ and three jellies without Ca ²⁺ , respectively (rupture + Ca) and (rupture-Ca).

4. Measure the amount of soluble solids. Measurements can be taken in metal containers for measuring IPPA temperature. The amount of soluble solid products should be 64.5-65.5%. Otherwise, the study should be repeated.

5. Measure the pH. It should be 2.95-3.05. Otherwise, the study should be repeated for a given amount of citric acid, see note.

Note:

Establishment of pH if it is outside the limits for analysis.

The amount of citric acid in ml can be calculated according to the following formulas if the pectin composition is known: x = pH in 1% solution

with calcium:

Lemon and lime pectins: 50% citric acid solution = 0.0094x2 + 0.8926x + 0.2004

Orange pectins: 50% citric acid solution = 1.1364x2 - 6.7409x + 12.775

calcium free:

Lemon and lime pectins: 50% citric acid solution = 0.0671x2 + 0.4573x + 0.8023

Orange pectins: 50% citric acid solution = 2.2727x2 - 14.482x + 25.551

The amount of citric acid is only estimated. The pH of the final product determines the amount of citric acid added. Formulas for calculating the amount of a 50% citric acid solution are generated by regressing a sufficient number of samples.

• Tensile strength and IPPA temperature at 60% for HM pectin (quick procedure)

Principle

The tensile strength is measured on a Texture Analyzer (TA-XT2) in synthetic jelly at 60% and pH 3.0. Tear strength is measured at a calcium level of 0 ppm. Ca ²⁺ (rupture-Ca ²⁺ ) and 90 ppm Ca ²⁺ (gap + Ca ²⁺ ).

Equipment:

1. Scales, maximum load 3-6 kg

2. Glass beakers, (1000 ml), 2 pieces

3. Volumetric flask, (1000 ml), 2 pieces

4. Magnetic stirrer

5. High speed mixer

6. Electric warm table, diameter: 15 cm, 1500 W

7. Saucepan, stainless steel, 1.5 L

8. Scoop

9. Stirrer at 500 rpm

10. Spindle of a mixer (HETO, article No. 000240, drawing No. 0004259)

11. Pipette

12. Thermostatically controlled water bath Haake D-8-G

13. Steel containers for samples (inner diameter 50 mm, inner height 74 mm) with lids

14. Petri dishes (lower part), diameter: 61 mm, height: 9 mm

15. Lids for Petri dishes

16. Oven at 25 ° C ± 2 ° C

17. Adhesive tape

18. Wire cutting for cheese

19. Texture Analyzer, type TA-XT2

20. Refractometer

21. pH meter

22. Stopwatch

23. Windows computer

24. Printer

25. IPPA temperature software (developed by CP Kelco)

№ buffer solution 1 (+ Ca ^2+): Potassium citrate monohydrate, K ₃ C ₆ H ₅ O _7, H ₂ O:
Calcium tetrahydrate citrate, Ca ₃ (C ₆ H ₅ O ₇ ) ₂ , 4H ₂ O: Sodium benzoate, C ₇ H ₅ NaO ₂ :
Citric acid, monohydrate, C ₆ H ₈ O ₇ , H ₂ O, 50% (w / v) 3.933 g
1,898 g
1000 g
25 ml (approximately)

900 ml of deionized water are dissolved in the indicated sequence and transferred quantitatively to a 1000 ml volumetric flask, which is filled to the mark with deionized water. The pH solution should be 3.4-3.5.

Buffer solution No. 2 (-Ca ²⁺ ): Potassium Monohydrate, K ₃ C ₆ H ₅ O ₇ , H ₂ O:
Sodium benzoate, C ₇ H ₅ NaO ₂ : 3.933 g
1000 g Citric acid, monohydrate, C ₆ H ₈ O ₇ , H ₂ O, 50% (w / v): 18 ml (approximately)

Dissolved as No. 1.

A solution of citric acid, 50% wt./volume:

Citric acid, monohydrate, C ₆ H ₈ O ₇ , H ₂ O: 500 g

Dissolve citric acid in deionized water and increase the mass with deionized water to 1000 ml in total.

Pectin solution:

Boiling water, deionized: 380 ml Pectin (grade 150 USA-SAG): x g

Dissolve the pectin in a high speed mixer for 5 minutes. Cool the solution to ambient temperature and increase the mass to 400 g, and mix in a high-speed mixer. Weigh out 121 g of a solution of pectin in a 250 ml glass beaker.

Calculation of x g pectin:

(8.7 x 150) / (estimated degrees of USA-SAG) = x g

Recipe:

The amount of soluble solid products%: 60.0 ± 0.5 pH: 3.0 ± 0.05

Gel + Ca ²⁺ :

Buffer solution No. 1: 135 g Sugar: 355 g Deionized Water: 30 g Pectin solution: 120 g Citric acid solution, approximately
50% (w / v): 3 ml (estimated amount) Generally: 643 g (approximately) Evaporation: 43 g (approximately) Final output: 600 g

Gel -Ca ²

Buffer solution No. 2: 135 g Sugar:
Deionized Water:
Pectin solution:
Citric acid solution approximately
50% (w / v): 355 g
30 g
120 g
2.5 ml (estimated amount) Generally: 642.5 g (approximately) Evaporation: 42.5 g (approximately) Final output: 600 g

Procedure:

The IPPA temperature, which is the gelation temperature of the gel obtained in accordance with the above composition, is determined, and a sample of the solution is prepared with and without calcium.

1. Launch the program. Use the following settings:

• Initial temperature: 95 ° C

• Final temperature: 15 ° C

• Temperature gradient: 1 ° C / min

• Enter file name

2. Fill the deionized water in a metal container and place it in a thermostatically controlled Haake D-8-G water bath.

3. Place the reference sensor in the middle of the container and press START. After that, the water bath will be heated to the initial temperature.

4. Weigh the buffer solution in an enamel pan (diameter 16 cm, internal height 7.5 cm). Add sugar and start the stopwatch. Heated to boiling with stirring (500 rpm).

5. Pectin solution from 250 ml glass beaker (120 g) is added and scraped off (residue in a beaker about 1 g), and boiling and stirring are continued.

6. Continue boiling for 1 minute

7. Add the calculated amount of citric acid solution. Continue boiling and mix for 30 seconds.

8. Increase the mass to 600 g with deionized water or boil for evaporation. (In practice, a slightly larger amount of water may be added to achieve properly soluble solid products).

9. Remove the pan from the heat and mix using a scoop. Leave for 20 seconds before removing all foam.

10. Fill two sample containers, with lids, for the Haake D-8-G thermostatically controlled water bath and place the sensors in the middle of the containers. Press the green PRE TO GO ON button. After the temperature difference drops to a temperature of less than 2 ° C, cooling starts. Finally, the computer calculates the gelation temperature.

Determination of tensile strength:

1. Fill, immediately after stage 7, 3 Petri dishes (lower part) (diameter 61 mm, height 9 mm), all equipped with a shell of tape.

2. Cover the Petri dishes with lids to prevent the gel from drying out when standing.

3. Leave the jelly for 18-24 hours at 25 ° C ± 2 ° C before measuring the tensile strength.

Gap:

1. Remove the casing from the tape and cut off the upper parts of the jelly using wire cutting for cheese flush with the top edge of the Petri dish.

2. Measure tensile strength on TA-XT2

• Distance traveled by the plunger: 6 mm

• Plunger diameter: 12.7 mm

• Plunger speed: 0.5 mm / s

3. The results are obtained as average values for three jellies with Ca ²⁺ and three jellies without Ca ²⁺ , respectively (rupture + Ca) and (rupture-Ca).

4. Measure the amount of soluble solids. Measurements can be taken in a metal container for measuring IPPA temperature. The amount of soluble solid products should be 59.5-60.5. Otherwise, the study should be repeated.

5. Measure the pH. It should be 2.95-305. Otherwise, the study should be repeated for a given amount of citric acid, see note.

Note:

Establishment of pH, if it is outside the limits for analysis

The amount of citric acid in ml can be calculated according to the following formulas if the pectin composition is known: x = pH in 1% solution

with calcium:

Lemon and lime pectins: 50% citric acid solution = 0.0094x2 + 0.8926x + 0.2004

Orange pectins: 50% citric acid solution = 1.1364x2 - 6.7409x + 12.775

calcium free:

Lemon and lime pectins: 50% citric acid solution = 0.0671x2 + 0.4573x + 0.8023

Orange pectins: 50% citric acid solution = 2.2727x2 - 14.482x + 25.551

The amount of citric acid is only estimated. The pH of the final product determines the amount of citric acid added. Formulas for calculating the amount of a 50% citric acid solution are generated by regressing a sufficient number of samples.

• Determination of the degree of USA SAG high ester pectin

Principle:

USA SAG is a method that measures the ability of pectin to bind sugars directly. The method considers a gel containing 65% soluble solids at a pH of 2.2-2.4, and that this gel settles by 23.5%. The method requires a series of gels to be prepared containing various concentrations of pectin. For a gel that meets the requirements, the ratio between pectin and sugar is calculated. If the ratio is 1: 150, pectin has 150 degrees USA SAG.

Equipment:

1. Analytical balance

2. Laboratory scales (maximum load 3-5 kg, accuracy 0.2 g)

3. Stainless steel pan, 1.5 L, diameter 15 cm

4. Electric warm table, diameter 15 cm, 1500 W

5. The motor of the mixer, adjustable speed, 500-1000 rpm

6. Stem of the mixer (HETO, article No. 000240, drawing No. 0004259)

7. Chemical beakers (1000 ml and 150 ml)

8. Spatula

9. Stopwatch

10. Thermometer, 100 ° C

11. pH meter

12. Glass and SAG tape

13. Ridgelimeter

14. Wire cutting for cheese

15. Refractometer

16. Incubator

Chemicals:

Sugar

Tartaric acid (488 g per liter of solution)

Deionized water

Jelly making:

1. Weigh in 1000 ml beaker 650 / (650-x) g sugar, (x = assumed pectin hardness).

2. Transfer 20-30 g of weighed sugar into a dry 150 ml beaker and add a weighed sample of pectin (the mass of pectin for use in jelly is expressed as: 650 g / estimated degree).

3. Pectin and sugar are thoroughly mixed in a glass by stirring with a spatula.

4. Pour 410 ml of deionized / distilled water into a 1500 ml enameled stainless steel pan and place the stirrer rod in it. Pectin / sugar mixture is poured into water - all at once - while stirring at 1000 rpm. Stirring is continued for two minutes. (It is important to immerse, as quickly as possible, a pectin / sugar solution in water and transfer any trace amounts of pectin / sugar in a small beaker to a pan).

5. After 2 minutes, the pan is placed on a preheated electric warm table and stirred at 500 rpm.

6. When the contents reach a fully developed boil, add the remaining sugar and continue heating and stirring until the sugar dissolves and until the total jelly load reaches 1015 g.

7. The electric warm table should be adjusted so that the total heating time for jelly is 5–8 minutes (full load, 1500 W).

8. After weighing 1015 g of the load on a laboratory balance, it is left without worrying on the table for one minute. Then fill the pan to the top, so that the contents almost flow over the edge, and quickly remove all the foam. Place the thermometer in the load and continue gently stirring until the temperature reaches exactly 95 ° C.

9. Quickly pour the load onto two pre-prepared glasses for the SAG method, each of which contains 1.75-2.25 ml of tartaric acid solution and is equipped with an adhesive tape, making it possible to fill approximately 1 cm above the edges of the glass.

10. After 15 minutes, the glasses are covered with lids and, when the temperature reaches 30-35 ° C, place the glasses in an incubator, at 25 ± 3 ° C, for 20-24 hours.

Measurement:

1. After 20-24 hours of storage, the jellies remove the covers from the glasses and remove the tape. Using wire cutting for cheese, cut off the top layer and discard.

2. Then gently turn the jelly from the glass to the upside down position on the square glass plate that comes with the Ridgelimeter .

3. Start the stopwatch as soon as the jelly is on the glass plate. If the jelly tilts slightly to one side, this can usually be adjusted by carefully tilting the glass plate in the other direction.

4. The plate and jelly are carefully placed on the Ridgelimeter base, so that the jelly is centered under the micrometer screw, which then must be screwed down next to the jelly surface.

5. Two minutes after the start of the stopwatch, the end of the micrometer screw is brought into contact with the jelly surface and the Ridgelimeter readings are recorded to the nearest 0.1.

6. Measure the pH if the SAG gel is loose or atypical by visual inspection or by touch. pH Must be between 2.2 and 2.4. Otherwise, the sample must be re-examined.

Calculation of the degree of jelly from pectin:

1. Using the Ridgelimeter calibration table, convert the Ridgelimeter reading to Factor 1.

2. Using the adjustment table for the amount of soluble solids, the measured amount of soluble solids is converted to Factor 2.

3. When the estimated degree is multiplied, for research, by correction factors, the true degree is obtained:

• Estimated Degree x Factor 1 x Factor 2 = True Degree

Ridgelimeler readings, percentage of SAG Factor 1 Ridgelimeler readings, percentage of SAG Factor 1 Ridgelimeler readings, percentage of SAG Factor 1 19.0 1,200 22.0 1,067 25.0 0.936 19.1 1,195 22.1 1,062 25.1 0.933 19.2 1,190 22.2 1,057 25,2 0.928 19.3 1,186 22.3 1,054 25.3 0.925 19,4 1,182 22.4 1,048 25,4 0.921 19.5 1,177 22.5 1,044 25.5 0.917 19.6 1,173 22.6 1,040 25.6 0.913 19.7 1,168 22.7 1,035 25.7 0.910 19.8 1,163 22.8 1,031 25.8 0,906 19.9 1,158 22.9 1,027 25.9 0.902 20,0 1,155 23.0 1,022 26.0 0.898 20.1 1,150 23.1 1.018 26.1 0.895 20,2 1,146 23,2 1.013 26.2 0.892 20.3 1,142 23.3 1.009 26.3 0.888 20,4 1,137 23,4 1.005 26,4 0.885 20.5 1,133 23.5 1,000 26.5 0.881 20.6 1,128 23.6 1,997 26.6 0.878 20.7 1,124 23.7 0,992 26.7 0.875 20.8 1,120 23.8 0.987 26.8 0.872 20.9 1,115 23.9 0.983 26.9 0.868 21.0 1,110 24.0 0.978 27.0 0.864 21.1 1,107 24.1 0.974 27.1 0.862 21,2 1.102 24.2 0.969 27,2 0.859 21.3 1,097 24.3 0.965 27.3 0.856 21,4 1,093 24.4 0.960 27.4 0.853 21.5 1,088 24.5 0.957 27.5 0.850 21.6 1,084 24.6 0.953 27.6 0.847 21.7 1,080 24.7 0.948 27.7 0.844 21.8 1,076 24.8 0.944 27.8 0.842 21.9 1,072 24.9 0.940 27.9 0.838

Calibration Table for Ridgelimeter

Correlation values calculated for "permutation" SAG analysis

Percent Correction Factor 2 64.0 1,034 64.1 1,031 64,2 1,028 64.3 1,024 64,4 1,021 64.5 1.018 64.6 1.015 64.7 1.012 64.8 1.008 64.9 1.004 65.0 1,000 65.1 0,997 65,2 0,993 65.3 0,990 65,4 0.987 65.5 0.984 65.6 0.980 65.7 0.975 65.8 0.970 65.9 0.967 66.0 0.964 66.1 0.960 66,2 0.957

Correlation values

• About molecular weight distribution for pectin

Principle:

Molecular weight is evaluated by measuring the relative viscosity of a 0.1% pectin solution using Na-hexametaphosphate.

Equipment:

1. Ostwald viscometer or similar (at least two) with an exit time for water (25 ° C) from 100 to 150 seconds.

2. Transparent thermostatic water bath, 25.0 ° C ± 0.3 ° C.

3. Digital stopwatch.

Reagents:

1. A solution of Na-hexametaphosphate:

a) 20.0 g of Na-hexametaphosphate are dissolved in 1800 ml of ion-exchanged deaerated (boiled) water.

b) the pH was adjusted to 4.50 ± 0.05 with 1 M HCl.

c) The solution is diluted with ion-exchanged, deaerated (boiled) water to a volume of 2000 ml.

Procedure:

1. Viscometers used must be cleaned as described in the section: Cleaning / Maintaining Viscometers.

2. The exit time for the hexametaphosphate solution is measured (section: Measurement of the exit time) on the used viscometers each time a new solution of hexametaphosphate is prepared, and each new working day when the pectin solution is measured. Immediately before measurement, the required amount of hexametaphosphate solution is filtered through a No. 3 glass filter.

3. A system of pectin samples for determining molecular weight is prepared as follows:

a) Wash pectin with acid as described in the method for determining AGA and DE (GENU Control Methods No. 378).

b) Approximately 90 g of the hexametaphosphate solution is weighed into an enameled beaker with a magnet.

c) Gradually, with stirring, 0.1000 g of acid washed pectin is added.

d) The solution is heated to 70 ° C with stirring. Stirring is continued until the pectin is completely dissolved.

e) The solution is cooled to 25 ° C

f) The mass is increased to 100.0 g with a hexametaphosphate solution.

g) Filter through No. 3 glass filter.

4. For each molecular weight determination, the exit time (section: Measuring the exit time) for the pectin / hexametaphosphate solution is measured on two different viscometers.

5. The molecular weight is calculated (section: Calculation) separately for each viscometer, using the most recently measured exit time for the hexametaphosphate solution on the viscometer in question.

6. If the difference between the two calculated molecular weights is less than 3500, an average value is calculated. The value is rounded to the nearest multiple of 1000, and it will be the result of the method.

7. If the difference between the two calculated molecular weights is 3500 or more, the viscometers should be cleaned and a new measurement of the exit time for the hexametaphosphate solution should be carried out.

Output Time Measurement:

1. The viscometer is washed twice with a sample.

2. Pour 5.00 ml of the sample into the viscometer and place it in a thermostated water bath at 25.0 ° C ± 0.3 ° C for at least 15 minutes before measurement.

3. Time is measured at two outputs. If the time difference is more than x seconds, the measurement is repeated until you have two consecutive measurements that differ by no more than x seconds.

• x = 0.2 seconds, when measuring a solution of hexametaphosphate

• x = 0.4 seconds, when measuring samples

4. The exit time, which is necessary for further calculations, is the average of the above two or three identical or almost identical measurement results.

Viscometer cleaning / maintenance:

1. After completion of work: washed once with ion-exchanged water, and then, once, with 1 M HCl.

2. Pour between work days: 1 M HCl.

3. On a working day, before measurement: washed twice in ion-exchanged (non-deaerated (boiled)) water.

4. Clogging: thoroughly washed with a thin copper wire.

Calculation:

The relative viscosity is calculated as follows:

n _r = {t ₀ - (K / t ₀ )} / (K / t _h )},

where t ₀ and t _h are the exit times for the pectin solution and the hexametaphosphate solution, respectively.

The parameter K can be detected with sufficient accuracy at a value of 107 sec ² , using an Ostwald viscometer. Otherwise, K can be calculated as follows:

K = {Q xt _v ² } / {Q + (0.226 x L xt _v )},

where Q = the volume of the flask of the viscometer in cm ³ , L = the length of the capillary tube in cm, and t _v is the exit time for water in seconds.

The molecular weight, M _w , pectin is calculated as follows:

M _w = {(n _r ^{1 / P} -1) x P} / kx C,

where P is fixed at a value of 6, and k is fixed at 4.7 · 10 ^-5 mol x g ^-1 ; C represents the percentage of mass pectin in the sample system - that is, 0.1%, when substituting numerical values, it turns out:

M = 1,277 · 106 (n _r 1/6 - 1) g / mol.

Literature:

Poul E. Christensen:

Methods of Grading Pectin in Relation to Molecular Weight (Intrinsic Viscosity) of Pectin.

Food Research, vol. 19, p. 163 - 171 (1954).

Christian J.B. Smit and Edwin F. Bryant:

Properties of Pectin Fractions Separated on Diethylaminoethylcellulose Columns. Journal of Food Science, vol. 32, p. 197-199 (1967)

• Determination of the degree of esterification (DE) and galacturonic acid (GA) in non-amide pectin

Principle:

This method relates to the determination of% DE and% GA in pectin, which does not contain an amide and acetate ester.

Equipment:

1. Analytical balance

2. Glass beaker, 250 ml, 5 pieces

3. Measuring glass, 100 ml

4. Vacuum pump

5. Vacuum flask

6. Crystallizer No. 1 with a glass filter (Buchner funnel and filter paper)

7. Stopwatch

8. Test tube

9. Oven, at 105 ° C

10. Descriptor

11. Magnetic stirrer and magnets

12. Burette (10 ml, accuracy ± 0.05 ml)

13. Pipettes (20 ml: 2 pieces, 10 ml: 1 piece)

14. pH meter / automatic burette or phenolphthalein

Chemicals:

1. Carbon dioxide-free water (deionized water)

2. Isopropanol (IPA), 60% and 100%

3. Hydrogen chloride (HCl), 0.5 N., smoking, 37%

4. Sodium hydroxide (NaOH), 0.1 N. (accurate to the fourth digit, for example, 0.1002), 0.5 n.

5. Silver nitrate (AgNO ₃ ), 0.1 N.

6. Nitric acid (HNO ₃ ), 3 N.

7. Indicator, phenolphthalein, 0.1%

Procedure - Determining% DE and% GA

(Acidic alcohol: 100 ml 60% IPA + 5 ml HCl, smoking, 37%):

1. Weigh 2,0000 g of pectin in a 250 ml glass beaker.

2. Add 100 ml of acidic alcohol and mix on a magnetic stirrer for 10 minutes.

3. Filter through a dry, weighed crystallizer with a glass filter.

4. The beaker is completely washed with 6 x 15 ml of acidic alcohol.

5. Wash with 60% IPA until the filtrate is free of chloride (approximately 500 ml).

(Chloride test: Transfer approximately 10 ml of the filtrate to a test tube, add approximately 3 ml of 3 N HNO ₃ and add a few drops of AgNO _3. The filtrate will not contain chloride if the solution is clear, otherwise silver chloride will precipitate.)

6. Wash with 20 ml of 100% IPA.

7. Dry the sample for 2 ½ hours at 105 ° C.

8. The mold is weighed after drying and cooling in a desiccator.

9. Carefully weigh 0.4000 g of sample in a 250 ml glass beaker.

10. Weigh out two samples for double determination. The absolute deviation between the two definitions should be a maximum of 1.5%. If the deviation exceeds 1.5%, the study should be repeated.

11. Pectin is moistened with approximately 2 ml of 100% IPA and approximately 100 ml of carbon dioxide-free deionized water is added while stirring on a magnetic stirrer.

After that, the sample is ready for titration, either by means of an indicator, or by using a pH meter / automatic burette.

Procedure - Determining Only% DE

(Acidic alcohol: 100 ml 60% IPA + 5 ml HCl, steaming, 37%):

1. Weigh 2.00 g of pectin in a 250 ml glass beaker.

2. Add 100 ml of acidic alcohol and mix on a magnetic stirrer for 10 minutes.

3. Filter through a Buchner funnel with filter paper.

4. Wash a beaker with 90 ml of acidic alcohol.

5. Wash with 1000 ml of 60% IPA.

6. Wash approximately 30 ml of 100% IPA.

7. Dry the sample for approximately 15 minutes on a Buchner funnel with vacuum suction.

8. Weigh approximately 0.40 g of sample in a 250 ml beaker.

9. Weigh two samples for double determination. The absolute deviation between the two definitions should be a maximum of 1.5%. If the deviation exceeds 1.5%, the study should be repeated.

10. Pectin is moistened with approximately 2 ml of 100% IPA and approximately 100 ml of deionized water is added while stirring on a magnetic stirrer.

After that, the sample is ready for titration, either by means of an indicator, or by using a pH meter / automatic burette.

Note: It is very important that samples with% DE <10% are titrated very slowly, since during the titration the sample will dissolve only very slowly.

Titration using indicator:

1. Add 5 drops of phenolphthalein indicator and titrate with 0.1 N. NaOH before color change (record this as a titer V1).

2. Add 20.00 ml of 0.5 N. NaOH, with stirring. Leave to stand for exactly 15 minutes. When it is standing, the sample should be covered with foil.

3. Add 20.00 ml of 0.5 N. HCl, with stirring, and stirred until the color fades.

4. Add 3 drops of phenolphthalein and titrate 0.1 n. NaOH before discoloration (record this as a V2 titer).

Blind test (double determination is carried out):

5 drops of phenolphthalein are added to 100 ml of carbon dioxide-free or deionized water (of the same type as used for the sample) and titrated in a 250 ml glass beaker of 0.1 N NaOH until discoloration (1-2 drops).

Add 20.00 ml of 0.5 N. NaOH and leave the sample to stand without touching it for exactly 15 minutes. When it is standing, the sample should be covered with foil.

Add 20.00 ml of 0.5 N. HCl and 3 drops of phenolphthalein, and titrated to a color change of 0.1 n. NaOH (record this as B1). The maximum amount allowed for titration is 1 ml 0.1 n. NaOH. If titrated with more than 1 ml, 0.5 n. HCl should be diluted with a small amount of deionized water. If the sample shows a discoloration upon addition of 0.5 N HCl, 0.5 N. NaOH should be diluted with a small amount of carbon dioxide-free water. The maximum allowable dilution with water is such that the solutions are between 0.52 and 0.48 n.

Titration using a pH meter / automatic burette:

When using an automatic burette type ABU 80, the following settings can be applied:

Sample with % DE <10 Blind test Proportionality range 0.5 5 Delay, sec fifty 5 Speed-V1 10 5 Speed-V2 fifteen 5

1. Titrate 0.1 n. NaOH to pH 8.5 (record the result as titer V1).

2. Add 20.00 ml of 0.5 N. NaOH, with stirring, and leave the sample to stand without stirring for exactly 15 minutes. When it is standing, the sample should be covered with foil.

3. Add 20.00 ml of 0.5 N. HCl, with stirring, and stirred until a constant pH is obtained.

4. After that, titrate 0.1 N. NaOH to pH 8.5 (record the result as titer V2).

Blind test (carry out double determination):

1. Titrate 100 ml of carbon dioxide-free or deionized water (of the same type as used for the sample) to a pH of 8.5 to 0.1 n NaOH (1-2 drops).

2. Add 20.00 ml of 0.5 N. NaOH, with stirring, and leave the sample to stand without stirring for exactly 15 minutes. When it is standing, the sample should be covered with foil.

3. Add 20.00 ml of 0.5 N. HCl, with stirring, and stirred until a constant pH is obtained.

4. Titrate to pH 8.5 0.1 N. NaOH (record this as B1). The maximum amount allowed for titration is 1 ml 0.1 n. NaOH. If titrated with more than 1 ml, 0.5 n. HCl should be diluted with a small amount of deionized water. If the pH does not drop below 8.5 with the addition of 0.5 N. HCl, 0.5 N. NaOH should be diluted with a small amount of carbon dioxide-free water. The maximum allowable dilution with water is such that the solutions are between 0.52 and 0.48 n.

Calculation:

• V _t = V ₁ + (V ₂ -B ₁ )

•% DE (esterification level) = {(V ₂ - B ₁ ) x 100} / V _t

•% DFA (free acid level) = 100 -% DE

•% GA * (galacturonic acid level) = (194.1 x V _t x n x 100) / 400

* In relation to the substance which is not containing moisture and ashes

194.1: Molecular Weight for GA

N: Corrected normality for 0.1 n. NaOH used for titration (e.g. 0.1002 N)

400: weight in mg of washed and dried titration sample

% Pure Pectin = {(amount of acid washed, dried pectin) x 100} / (weighted amount of pectin)

• sensitivity to calcium - CS-99-2

Principle:

The pH of the pectin solution was adjusted to 3.60 using 3.0 M Na-acetate buffer. The sample is dissolved by heating in a water bath at 75 ° C for 5-10 minutes. Then, 272 ppm is added to the sample. calcium (above 70 ° C). The viscosity of the sample is usually measured using an LVT viscometer, using a No. 1 or 2 spindle, at 60 rpm, 5 ° C, after 19 ± 3 hours. Measurement should be carried out without a protective feedback loop.

Equipment:

1. Glasses for measuring viscosity, inner diameter 48 mm, height 110 mm

2. Magnets approximately 30 mm long

3. Water bath (75 ° C) with magnetic stir bar

4. Foil or other heat-resistant coating material

5. 5 ml and 20 ml pipettes or dispensers

6. pH meter

Reagents:

1.190-100% IPA

2. A solution of CaCl ₂ (32 g / l CaCl ₂ , 2H ₂ O)

3. 3.0 M Na-acetate buffer.

Preparation of buffer for 2 liters of 3.0 M sodium acetate buffer, pH 3.60:

1. 81.64 g of Na-acetate, 3H ₂ O is dissolved in a beaker using approximately 1200 ml of ion-exchanged water.

2. The solution is transferred quantitatively to a 2000 ml volumetric flask.

3. In a fume hood, add 309 ml of 100% acetic acid, and the volumetric flask is filled to the level of ion-exchanged water.

5 liters: 204 g of Na-acetate, 3H ₂ O, 772 ml of 100% acetic acid.

The pH of the solution is 3.60 ± 0.05. If in doubt, check the pH.

Pectin solution concentration:

0.4%: 0.64 g of sample is weighed (non-standardized pectin)

0.5%: 0.80 g sample (standardized pectin) weighed

Procedure:

1. Weigh a pectin sample into a beaker for measuring viscosity.

2. Add 5.0 ml IPA

3. Stir the sample on a magnetic stirrer while adding 130 ml of boiling (above 85 ° C) water. It is important that the viscosity measuring cup is coated (i.e., with foil) throughout the mixing.

4. Add 20 ml of 3.0 M Na-acetate buffer, pH 3.60.

5. Stir the sample in a water bath at 75 ° C for a minimum of 5 minutes using a magnet. If the sample contains lumps, the dissolution procedure should be repeated.

6. Stir the sample using a vortex mixer, approximately 2 cm. Add 5 ml of a solution of calcium (CaCl ₂ , 2H ₂ O, 32 g / l). The maximum time to add is 2 seconds. The sample is stirred for approximately 10 seconds.

IMPORTANT:

If the vortex disappears while calcium is being added - and / or local gel formation or trapped air bubbles are observed - the sample is marked as prematurely forming a gel as a result of the analysis. If the sample is measured later as a normal sample, the result will be too low. Then the analysis can be carried out at a lower concentration of pectin.

7. Remove the magnet and cover the glass, for example, with foil.

8. Place the sample in a water bath, 5 ° C, for 19 ± 3 hours. Make sure that the water level of the water bath is the same as the surface level of the sample.

9. If air bubbles are present on the surface of the sample, they are carefully removed before measuring the sample. Measure the viscosity after 1 minute, at 5 ° C, using an LVT viscometer, using a No. 2 spindle, at 60 rpm. For results below 10, on a viscometer, the measurement is carried out using spindle No. 1. For results above 100, the sample is placed in a water bath at 5 ° C for 19 ± 3 hours. Then measure the viscosity using a spindle No. 3, at 60 rpm

Use the appropriate coefficient to calculate the viscosity (cP - centipoise). The CS value is equal to the calculated viscosity.

• Transparency of 1% pectin solution - cold solution

Principle:

The transparency of a 1% pectin solution is determined using a spectrophotometer.

Equipment:

1. Beaker, 250 ml

2.100% IPA

3. Magnet

4. Magnetic stirrer

5. Deionized water

6. Volumetric flask, 100 ml

7. Pipette

8. Spectrophotometer

Procedure:

1. Weigh 1 g pectin in a 250 ml beaker.

2. Wet 3 ml of IPA.

3. Place the magnet in a beaker.

4. Place the beaker on a magnetic stirrer,

5. Add 96 ml of deionized water, with stirring.

6. Stir until pectin dissolves.

7. Measure the passage or absorption on a spectrophotometer, at 655 nm.

8. Get the results as% T (passage) or% Abs (absorption).

• Determination of residual sugar in the peel

Goal:

Determination of residual sugar in the peel is carried out by washing with 50% isopropanol.

Equipment:

1. Glass beaker, 600 ml

2. Scales (accuracy 0.2 g)

3. Magnetic stirrer

4. Magnet

5. Paper filters (coarse), for example, type AGF 614

6. Oven, at 65-70 ° C

7. Buchner funnel

8. The vacuum pump

Solutions:

Isopropanol, 50%

Procedure:

1. Weigh 10 g of the peel sample in a 600 ml glass beaker.

2. Add 200 ml of 50% isopropanol.

3. Stirred for 4 hours on a magnetic stirrer.

4. Wash the peel and filter with 250 ml of 50% isopropanol.

5. Place the filter and sample in an oven, at 65-70 ° C, overnight, and weigh.

Calculation of residual sugar in the peel,%:

{(SS x 10) - (net x 95)} x 100 / (SSx 10), where

SS = percentage of dry material before washing and drying

Net = mass of washed and dried peel

95 = set percentage of dry material in washed and dried peels

• Determination of pH in HM and LM pectins - cold solution

Principle:

The pH is determined in a 1% cold prepared pectin solution.

Materials:

1. Beaker, 250 ml

2.100% IPA

3. Magnet

4. Magnetic stirrer

5. Deionized water

6. Pipette

7. pH meter

Procedure:

1. Weigh 1 g of pectin in a 250 ml beaker.

2. Wet 3 ml of IPA.

3. Place the magnet in a beaker.

4. Place the beaker in the mixer.

5. Add 95 g of deionized water.

6. Stir until pectin dissolves.

7. Calibrate the pH meter using buffer solutions, at pH 7.00, prepared from potassium hydrophthalate and disodium hydrogen phosphate; and at a pH of 4.01 prepared from potassium hydrophthalate, respectively, at 25 ° C. Both buffers should be dissolved in water obtained by reverse osmosis, and then double ion exchange. After that, the pH of the pectin solution is measured at 25 ° C.

• Determination of drying loss of HM and LM pectin

Principle:

Losses during drying are determined by drying a known amount of pectin for 2 hours, at 105 ° C, in an oven.

Equipment:

1. Oven, at 105 ° C

2. Test beaker

3. Analytical balance

4. Desiccator

Method:

1. Dry the test beaker for at least 30 minutes at 105 ° C. Cool the test beaker in a desiccator and weigh it.

2. Transfer a known amount, for example 2,000 g of pectin, into a test beaker.

3. Place a test beaker with pectin in an oven at 105 ° C for 2 hours.

4. Cool the test beaker with pectin in the desiccator and weigh it.

Drying loss is calculated:

% loss upon drying = {(g of dried pectin - g of dried pectin)} x 100 / (g of dried pectin)

• Determination of plant esterase activity

Principle:

Hydrolysis of methyl esterase bonds in pectin at constant pH. The need for a titrant is measured as a function of time and activity is measured as

One unit = moles of demethylated carboxyl groups per minute.

Equipment:

1. Analytical balance (accuracy 0.1 g).

2. Water bath at 5 ° C.

3. Stopwatch.

4. pH meter.

5. The mixer motor, adjustable, 50 - 2000 rpm.

6. The centrifuge.

7. Blender Waring.

8. Title device

Chemicals and solutions:

1. Sodium chloride, analytical quality.

2. Sodium hydroxide, analytical quality.

3. Sodium bicarbonate, analytical quality.

4. Subjected to ion exchange water with a conductivity below 1 mS / cm.

5. 0.0625 M sodium bicarbonate.

6. 1 M sodium bicarbonate.

Procedure:

1. Grind the peel.

2. Weigh 50.0 g of the peel and transfer it to a 2.01 plastic beaker.

3. Add ion-exchanged water to obtain a working consistency.

4. Add sodium chloride to a concentration of 1 mol.

5. The pH was adjusted to 6.0 with 0.5 M sodium hydroxide.

6. Place a plastic beaker in a water bath, 5 ° C, and mix slowly for 2 hours. Set the pH every half hour.

7. Centrifuge the mass at 9000 rpm for 30 minutes.

8. Remove the supernatant to determine the activity of plant esterase.

9. A pectin solution is prepared by dissolving 20.0 g of citrus pectin having a DE of 72% and 23.4 g of sodium chloride in 700 ml of boiling, ion-exchanged water by stirring in a Waring blender for 3-4 minutes.

10. Cool the pectin solution to room temperature and bring the total weight to 1000 g.

11. Heat 100.0 g of pectin solution to 60 ° C

12. Adjust the pH of the pectin solution to 5.50 with 1 M sodium hydrogen carbonate and immediately add 5 ml of the supernatant indicated above. The amount of supernatant may be greater than 5 ml, or less than 5 ml, depending on the actual activity of plant esterase in the supernatant.

13. Start titration with 0.0625 M sodium bicarbonate and record the titration curve.

14. The slope (p) of the linear portion of the titration curve is determined.

15. Calculate the activity of plant esterase as units / ml = p x 62.5 / ml supernatant.

The method for determining the acid treatment of the starting plant material containing pectin:

One way to determine whether pectin-containing plant feed was treated with acidified water is to use the following study to determine the pH of a pectin-containing plant feed. This study is useful for pectin-containing plant starting material that initially has a pH above 4. Examples of such pectin-containing plant starting materials are orange, grapefruit, fodder beets, sugar beets, apples and carrots. For plant feed materials containing pectin that initially have a pH of 4 or lower, other means should be used to determine whether the feed plant material containing pectin was treated with acidified water.

In the study of dry peels, ten grams (10 g) of sample are obtained and the sample is added to a beaker. When a wet peel is examined, the size of the sample increases to fifty grams (50 g).

Add 150 ml of deionized or distilled water to a beaker.

Stir the peel / water mixture for 15 minutes using a bar of a magnetic stir bar at ambient temperature.

After 15 minutes, measure the pH. Preferably, the pH is measured using a pH meter such as pH M290 (available from Radiometer) equipped with an electrode such as PHC2401-8 (available from Radiometer).

For example, a dried plant material containing pectin exhibiting a pH below 5 would indicate a material that was treated with acidified water, preferably a dried plant material containing pectin exhibiting a pH of below about 4.4, more preferably below about 4 , 0, even more preferably, exhibiting a pH in the range between 4.0 and 3.5.

Examples

The following examples are offered by way of illustration, but not by way of limitation.

• Comparative example

This example repeats the method of processing orange peel, as described in US patent 2387635 (Bailey, H.S.).

8 liters of chopped orange peel (measured by crowding out) is added to 4.67 liters of boiling water. A quantity of 62% nitric acid is added to give a pH in the range of 2.8-3.6, during heating. It is believed that an amount of 80 ml of 62% nitric acid provides a pH of 3.4 during heating. The relatively high amount of acid needed to lower the pH is due to the relatively high buffer capacity of the fresh peel and the low amount of added water. After 10 minutes, the mass is cooled and the peel is separated on a sieve. Then the peel is squeezed using a hydraulic press and the squeezed peel is spread in a thin layer on several drying trays and dried at 70 ° C in an oven at atmospheric pressure.

500 g of dried peel was subsequently extracted in accordance with the “Pectin Extraction” method, and the obtained pectin was labeled as Comparative Example 1.

Results:

Sample %
Sahara HNO ₃
during extraction,
ml pH
extract at
25 ° C Precipitated Extract
g Pectin, g Yield g / l Plant Esterase Activity Unit / g Comparative Example 1 49.0 60 1.76 12725 79,20 6.22 0

Sample Sag Exit
% Pectin purity% DE
% GA
% Mw TS
% pH
one% T *
% Comparative Example 1 177 ° 18.7 97.7 67.9 78.6 82000 96.4 3.36 68.3

*: Passage

From this example, it can be seen that the method used in US Pat. No. 2,387,635 yields high sugar content orange material. Thus, the method described in US Pat. No. 2,387,635 does not effectively remove sugars from the orange peel. In addition, with a high sugar content in the peel, the resulting pectin yield is low. When looking at the resulting pectin, the USA SAG is low, and the molecular weight is the same. This indicates that pectin is depolymerized during the next heating of the orange peel / water suspension. Finally, this example demonstrates that by heating the orange peel / water suspension to about 90 ° C, the activity of plant esterase is completely eliminated.

Example 1

In this example, the acid treatment is carried out at room temperature and with a higher amount of water.

8 liters of chopped orange peel (measured by displacement) is added to 24 liters of water, to which a certain amount of acid is added in advance, to achieve a pH of the peel / water mixture in the range of 2.8-3.6. It is assumed that an amount of 20 ml of 62% nitric acid results in a pH of 3.2 for the peel / water mixture. The peel / water mixture was stirred at room temperature for 15 minutes. After this period, the peel is separated from the liquid and the extracted peel is squeezed under slight pressure on a hydraulic press to remove excess water, without crushing the peel. Then the pressed peel is added to 24 liters of fresh water, to which a certain amount of acid has been added before, to achieve a pH of the peel / water mixture in the range of 2.8-3.6. An amount of 15 ml of 62% nitric acid is believed to result in a pH of 3.2 for the peel / water mixture. The lower amount of acid needed at this stage is explained by the first stage, which was supposed to remove some of the natural acid of the peel. The peel / water mixture was stirred at room temperature for 15 minutes, and then the peel was separated from the liquid. The extracted peel is squeezed under slight pressure on a hydraulic press to remove excess water, without crushing the peel. This last washing step is repeated, after which the peeled and squeezed peel is spread in a thin layer on several pallets and dried at 70 ° C, in an oven, at atmospheric pressure.

500 g of dried peel is then extracted in accordance with the method "Extraction of pectin" and the resulting pectin is labeled as example 1.

Results:

Table 1.1

Sample %
Sahara HNO ₃
during extraction, ml extract pH at
25 ° C Precipitated Extract
g Pectin, g Yield g / l Plant esterase activity, units / g Example 1 16.8 60 1.74 8300 82.60 9.95 42

Table 1.2

Sample Sag Exit
% Pectin purity% DE
% GA
% Mw TS
% pH
one% T *
% Example 1 213 ° 29.9 94-9 63.7 83,2 101000 96.3 3.34

*: Passage

This example demonstrates that when the method of the present invention is applied, less sugar remains in the peel washed with acid, and as a result, the yield of pectin increases dramatically. In addition, washing with acidified water gives an increase in both USA SAG and molecular weight, compared with comparative example, in fact, the ratio of USA SAG of example 1, when compared with USA SAG of comparative example, is equal to 1.20. Thus, by treating the orange peel of the present invention, a 20% increase in USA SAG is achieved. Accordingly, the ratio between the molecular weight of pectin obtained in Example 1 and pectin obtained in Comparative Example is 1.23. Thus, the molecular weight is increased by 23% when the orange peel is processed in accordance with the present invention.

Example 2

In this example, the comparative example is repeated with fresh oranges directly taken from an orange tree. However, this example uses steam instead of boiling water. The procedure is the same as in example 1. However, after washing with acidified water three times, the slightly wrung out peel residue is placed in a Buchner funnel. A tube is connected to the exit of the Buchner funnel and then steam is injected into the peel through the tube. Steaming continues for 3 minutes. Using a thermocouple, the temperature inside the peel is measured, and it is assumed that a temperature of 90 ° C is reached after 2 minutes of steaming. After steaming, the peel is further processed as in Example 1. The resulting pectin is labeled “D”.

Results:

Table 2.1

Sample M _w Sag DE
% Tensile strength + Ca / -Ca Break
-Ca Break
+ Ca "D" 93800 205 ° 66 195 201 1,03

For a completely fresh orange peel, the USA SAG is about 16% higher than in the comparative example. Similarly, the molecular weight is about 14% higher.

Example 3

This example is based on example 1, with the exception that the orange peel used is the orange peel of example 2. Thus, the treatment is carried out at room temperature, the peel is washed three times, at pH 3.5, followed by drying. The dried peel is extracted in the same manner as in examples 1 and 2.

Results:

Table 3.1

Sample M _w Sag DE
% Tensile strength + Ca / -Ca Break
-Ca Gap + Ca "C" 116900 229 ° 68 156 185 1.19

This example demonstrates that washing with acidified water leads to an increase in both the USA SAG and molecular weight compared to the comparative example. In fact, the USA SAG ratio of Example 3 compared to Example 2 is 1.12. Thus, by treating the orange peel of the present invention, a 12% increase in USA SAG is achieved. Accordingly, the ratio between the molecular weight of the pectin obtained in example 3 and the pectin obtained in example 2 is 1.25. Thus, the molecular weight is increased by 25% when the orange peel is processed in accordance with the present invention. Thus, regardless of the freshness of oranges, the present invention provides a significant increase in both the USA SAG and the molecular weight of the resulting pectin.

Example 4

The present invention scales to 1000: 1, and the method is carried out in a few days. Thus, the fresh peel is washed with water in a 4-stage countercurrent method. The resulting pH of comparative examples ranges between 4.5 and 5.2. For washing with acid, the pH is adjusted to 3.4-3.6. Processing takes place at 30 degrees C. After washing, the peel is dried continuously.

Samples were taken throughout the study and these samples were extracted according to the recipe used in example 1.

Results:

Table 4.1

Treatment Sag Tensile strength + Ca / -Ca -Ca + Ca Fresh Water (Comparative) 228 ° 151 121 0.80 Fresh Water (Comparative) 232 ° 180 131 0.73 Fresh Water (Comparative) 234 ° 133 110 0.83 Acid flushing (Example) 240 ° 151 143 0.95 Acid flushing (Example) 235 ° 254 239 0.94 Acid flushing (Example) 224 ° 171 168 0.98 Acid flushing (Example) 228 ° 239 246 1,03 Acid flushing (Example) 235 ° 202 193 0.96 Acid flushing (Example) 238 ° 184 209 1.14

When using fresh water or acidified water, the SAG values are not significantly different. However, looking at the relationship between the tensile strengths obtained with and without calcium, the peel treated with fresh water gives pectin with a ratio below 0.83. The peel, washed with acidified water, gives pectin with a specified ratio above 0.94. This demonstrates that peel treated with acidified water gives pectin with a significantly lower sensitivity to calcium. In fact, calcium-containing gels prepared from pectin obtained by washing the peel in fresh water show clear evidence of premature gelation, while this phenomenon is not observed in the corresponding gels prepared from pectin washed with acidified water.

Example 5

This example is provided to demonstrate the effect of washing temperature with acidified water on dried peel and obtained pectin.

Use approximately 25 kg of fresh orange peel. The peel is crushed and processed, as explained below.

In comparative example 5, a third of the peel is washed 3 times without acid. The pH of the wash water is measured as pH 5.18.

The remainder of the peel is treated with acidified water, at this last stage the mixture is heated to various temperatures.

Acidified water flushing

The peel is stirred for 15 minutes at room temperature, with 3 volumes of water. The pH was adjusted to 3.5 with nitric acid, and then the peel was separated on a “drip tray”. Use caution when adding acid to water before adding peels.

The peel is slightly squeezed on a hydraulic press to remove excess acidified water. Use caution to prevent crushing of the peel.

The peel is reloaded into a second portion of 3 volumes of water and the pH adjusted to 3.5. The mixture of peel and acidified water is mixed for an additional 15 minutes. The peel is separated on a drying tray.

The peel is wrung out, as in the previous stage.

The peel is divided into two (2) servings of the same size.

The procedure is repeated for the third time with three 3 volumes of water, and the pH is adjusted to 3.5. pH is recorded before peeling on a drying tray. In the third and final stage of washing with acidified water, various temperatures are used. Example 5a was washed at 25 ° C. Example 5b was washed at 65 ° C.

All peel examples are squeezed using a hydraulic press to remove excess water. The pressed processed peel is distributed on several drying pallets. Then the pressed processed peel is dried in an oven at approximately 70 ° C, and with a sufficient flow of air, overnight (approximately 15 hours) until it is considered “dried”.

Table 5.1

Example Water
(l) pH peel pH Comp. pr 5 60 5.18 6.25 Example 5a thirty 3.45 3.94 Example 5b thirty 3.47 3.76

All samples were extracted using modified standard extraction of HM pectin in 50-liter containers: (2.5 hours, 75 ° C, 1000 grams of peel, 40 liters of water, pH 1.9-2.1).

After extraction, the samples are filtered through diatomaceous earth, ion-exchanged using 50 ml of resin (Amberlite SR1L from Rohm & Haas) per liter of juice, and precipitated, 1: 3, in 80% IPA, followed by washing in 60% IPA.

Results:

Table 5.2

Example HNO ₃
(ml) PH extract. juice
25 ° C The mass of precipitated juice (g) Mass of pectin
(g) Yield (g / l *) Comp. Example 5 80 2.06 10,000 42 4.2 Example 5a 55 2.12 10,000 41 4.1 Example 5b 55 2.07 10,000 51 5.1

* On diluted juice.

Table 5.3 Example Sag % DE % GA 1% viscosity M _w CS-99
+ CA Comp. example 5 198 73? 1 78.9 60 125203 270 Example 5a 214 74,2 79.0 52 146381 24 Example 5b 211 73? 2 77.5 53 141683 27

This example demonstrates that the method of the present invention can be carried out at temperatures from ambient temperature to at least 65 ° C. This keeps the CS low, without changing the SAG.

Example 6

The procedure of example 5 is repeated.

In comparative example 6, a third of the peel is washed 3 times without acid. The pH of the wash water is measured as a pH of 4.89.

In Example 6a, the final washing with acidified water was carried out at 25 ° C. In Example 6b, the final washing with acidified water was carried out at 70 ° C.

Table 6.1 Example Water
(l) pH peel pH Reference Example 6 60 4.89 5.21 Example 6a thirty 3.75 3.98 Example 6b thirty 3.72 3.91

Results:

Table 6.2 Example HNO ₃
(ml) pH extraction juice
25 ° C The mass of precipitated juice
(g) Mass of pectin
(g) Yield (g / l *) Comp. Example 6 80 2.04 10,000 37 3.7 Example 6a 55 2.06 10,000 52 5.2 Example 6b 55 1.93 10,000 56 5,6

* On diluted juice.

Table 6.3 Example Sag % DE % GA 1% viscosity M _w CS-99
+ CA Comp. Example 6 193 74,2 81.1 122 112751 285 Example 6a 212 74,4 80.3 91 140340 52 Example 6b 204 73.9 80.1 87 135520 68

This example demonstrates that the method of the present invention can be carried out at temperatures ranging from ambient temperature to at least 70 ° C. This keeps the CS low, without changing the SAG.

Example 7

This example is given to demonstrate the effect of washing with acidified water on dried peels and on the resulting pectin produced from citrus fruits other than orange, namely grapefruit.

About 30 kg of fresh grapefruit is squeezed to produce juice and the peel is crushed, as in example 5.

In comparative example 1, the crushed peel is mixed with 3 volumes of water for 15 minutes at room temperature. The pH of the water is recorded after 15 minutes of stirring and the peel is separated on a drying tray.

Peel slightly squeezed on a hydraulic press to remove excess water. Be careful to prevent crushing of the peel.

The peel is reloaded into a second portion of 3 volumes of water and mixed for an additional 15 minutes at room temperature. The pH of the water is recorded after 15 minutes of stirring and the peel is separated on a drying tray.

This washing step is repeated a third time.

The pressed treated peel is then dried in an oven at approximately 70 ° C and with sufficient air flow overnight (approximately 15 hours) until it is considered to be “dried”.

Acidified water flushing

In example 7, the peel is treated as in comparative example 7, except that the peel is washed with acidified water containing 9 ml of 62% HNO ₃ at a pH of from 3.5 to 3.8. Use caution when adding acid to water, before adding the peel, to ensure that the peel does not come into contact with concentrated acid.

Table 7.1 Example Water
(l) HNO ₃
(ml) pH Weight
peel
(g) Comp. example 7
1 flushing 22 - ~ 4.2 - 2 flushing 22 - ~ 5.7 - 3 flushing 22 - ~ 6.2 523 Example 7
1 flushing 22 9 + 2 ~ 3.6 - 2 flushing 22 8 + 3 ~ 3.6 - 3 flushing 22 11 + 1 ~ 3,5 601

All examples of dried peels are extracted using the following pectin extraction method.

15 l of water are charged into a small squeeze centrifuge at 70 ° C. Then five hundred grams (500 g) of dried peel was added to the squeeze centrifuge and the pH of the water was adjusted to 1.7 by adding 62% HNO ₃ .

Additional acid can be added to the squeeze centrifuge after 15 minutes, if necessary, to maintain the pH. Extraction continues at a temperature of 70 ° C and a pH of 1.7 for 7 hours.

After extraction, the samples are filtered through diatomaceous earth, subjected to ion exchange using 50 ml of resin (Amberlite SR1L from Rohm & Haas) per liter of juice, and precipitated, 1: 3, in 80% IPA, followed by washing in 60% IPA. The resulting pectin is dried in an oven and the mass of pectin obtained is determined.

Results:

Table 7.2 Example HNO ₃
(ml) pH of juice
25 ° C pH
juice
25 ° C, after 1 hour of extraction Viscosity,
70 ° C
cp The mass of precipitated juice (g) The mass of pectin (g) Yield (g / l) Filter time
(min) Comp.
example 7 60 1,69 1,69 4.0 4530 23.17 6.8 40 Example 7 52 1.68 1.68 6.5 4705 28.23 8.0 40

Table 7.3 Example Exit % R% DE% GA% M _w Sag 1% pH one%,
T CS-99-Ca CS-99 + Ca Comp. note 7 20.5 98.2 60.7 86.2 99 220 ° 3.40 80.6 6.0 675.0 Example 7 24.0 98.0 66.7 85.8 125 241 ° 3.46 84.1 18.5 342.5

This example demonstrates the improvement of pectin obtained from processed dried grapefruit peel when compared with pectin obtained from untreated dried grapefruit peel.

Example 8

This example is given to demonstrate the effect of washing with acidified water on dried peels and obtained pectin produced from fruits other than citrus fruits, namely apples.

Get fifty (50) kg of apples (Belle de Bosfcoop). The peel from the apples is prepared as in example 7.

Table 8.1 Example Wet peel
(kg) Water (L) HNO ₃
Ml
Flushing 1 / pH HNO ₃
ml
Flushing 2 / pH HNO ₃
ml
Flushing 3 / pH Dry peel
(kg) Comp. approx. 8 15.7 45 - / 3.63 - / 6.13 - / 6.88 0.465 Example 8 16.5 fifty 0 ml / 3.81 22 ml / 3.78 22 ml / 3.79 0.564

Samples were extracted using modified standard extraction of HM pectin in 18 liter containers: (7 hours, 70 ° C, 450 grams of peel, 13.5 liters of water, acid, as described).

After extraction, the samples are filtered through diatomaceous earth, subjected to ion exchange using 50 ml of resin (Amberlite SR1L from Rohm & Haas) per liter of juice, and precipitated, 1: 3, in 80% IPA, followed by washing in 60% IPA.

Results:

Table 8.2 Example HNO ₃
(ml) Sugar,% pH of the extracted juice
25 ° C The mass of precipitated juice
(g) Mass of pectin Yield (g / l *) Comp. Example 8 60 1.80 1.75 4540 16.76 3.6 Example 8 49 2.02 1.75 7170 31.03 4.3

Table 8.3 Example Sag % R % DE % GA Mw % TS one%,
pH CS-99
-Ca CS-99
+ Ca BS
+ Ca BS-CA % T Comp.
example 8 176 ° 96.2 64.7 80.3 149316 96.7 2.96 12 105 * _ * _ 64 Example 8 192 ° 98? 4 65.8 83,2 165436 98.1 2.89 fifteen 34 * 107 * 92 68

This example demonstrates the improvement of pectin obtained from processed dried apple peel when compared with pectin obtained from untreated dried apple peel. The result is a high M _w , a higher SAG value and a lower CS value.

Example 9

In this example, Example 1 is repeated on an industrial installation, that is, Example 1 is scaled to 1000: 1. One charge is treated in accordance with Example 1 with an acid, while the other charge is treated in accordance with Example 1, however, without washing with acid. Thereafter, the dried peel charge is measured in accordance with the “Method for Determining Acid Treatment of Pectin-Containing Plant Material”. In addition, the activity of plant esterase is determined in both downloads in accordance with the method "Determination of plant esterase activity."

results

Sample peel pH Plant Esterase Activity
units / g Acid treated 4.03 41 Untreated acid 4.44 fifteen

Sample ° SAG DE
% GA
% CS-99 + Ca BS
+ Ca BS
-Ca BS + Ca / BS-Ca Acid treated 226 64.3 83.9 17 118 121 0.98 Untreated acid 227 65.3 82.1 72 103 143 0.72

This example demonstrates that enzyme activity in an orange peel is maintained during acid treatment in accordance with the present invention.

In addition, this example demonstrates that the acid treatment of the present invention provides pectin obtained from an acid-treated orange peel that is substantially less sensitive to calcium than pectin obtained from the same orange peel that is not acid-treated.

The lower sensitivity to calcium is further illustrated by the fact that acid treatment leads to a higher relationship between the tensile strength of the gel obtained with the addition of calcium ions, compared with the tensile strength of the gel obtained without the addition of calcium ions.

Although the foregoing invention has been described in detail for purposes of clarity, it will be apparent that certain modifications may be made within the scope of the appended claims.

Claims (30)

1. A method of obtaining a processed starting plant material containing pectin by deactivating pectin esterase, characterized in that the starting plant material of fruits containing pectin is obtained, bringing it into contact with acidified water having a pH value in the range from 3.2 to 3 , 9, at a temperature of ≤70 ° C, after which the processed starting plant material is recovered. 2. The method according to claim 1, in which acidified water has a pH value in the range from 3.4 to 3.7. 3. The method according to claim 1, in which acidified water is obtained by acidification using an inorganic or organic acid. 4. The method according to claim 1, wherein the acidified water is acidified using an inorganic acid selected from hydrochloric acid, sulfuric acid, sulfur dioxide and nitric acid. 5. The method according to claim 1, wherein the acidified water is acidified using an organic acid selected from the group consisting of citric acid, oxalic acid and acetic acid. 6. The method according to claim 1, in which acidified water is acidified using a buffer system capable of maintaining the pH of acidified water in the range from 3.2 to 3.9. 7. The method according to claim 5, in which the buffer solution is able to maintain the pH of acidified water in the range from 3.4 to 3.7. 8. The method according to claim 6, in which the buffer system is selected from the group comprising hydrochloric acid / disodium hydrocytrate, glycine / hydrochloric acid, potassium hydrophthalate / hydrochloric acid, citric acid / sodium citrate and sodium acetate / acetic acid. 9. The method according to claim 1, in which the specified source of plant material containing pectin is brought into contact with acidified water at a temperature of ≤50 ° C. 10. The method according to claim 9, in which the specified source of plant material containing pectin is brought into contact with acidified water at a temperature of ≤30 ° C. 11. The method according to claim 1, further comprising the step of drying the treated starting plant material containing pectin to obtain a processed dried starting plant material containing pectin. 12. The method according to claim 1, in which the source of plant material containing pectin is selected from the group consisting of citrus fruits and apples. 13. The method according to claim 1, in which the starting plant material containing pectin includes citrus fruits. 14. The method according to item 13, in which the source of plant material containing pectin, includes oranges. 15. The method according to item 12, in which the source of plant material containing pectin, includes apples. 16. The processed source plant material containing pectin, characterized in that it is obtained by the method according to any one of claims 1 to 15 for use in the extraction of pectin. 17. The processed pectin containing plant starting material according to claim 16, wherein the treated pectin containing plant starting material exhibits a pH below 4.5 when it is extracted with deionized water. 18. The processed pectin containing plant starting material according to claim 17, wherein the treated pectin containing plant starting material exhibits a pH below 4.0 when it is extracted with deionized water. 19. The processed pectin containing plant starting material according to claim 18, wherein the processed pectin containing plant starting material exhibits a pH of from 4.0 to 3.5 when it is extracted with deionized water. 20. The processed plant material containing pectin, according to clause 16, in which the processed plant material containing pectin, includes citrus peel. 21. The processed pectin containing plant starting material according to claim 20, wherein the processed pectin containing plant starting material includes dried citrus peel. 22. The processed plant material containing pectin, according to item 21, in which the processed plant material containing pectin, includes dried orange peel. 23. A processed source of plant material containing pectin, characterized in that it is obtained by the method according to any one of claims 1 to 15 for use as animal feed. 24. A processed source of plant material containing pectin, characterized in that it is obtained by the method according to any one of claims 1 to 15, for use as an ingredient in food products. 25. Pectin obtained by extraction from a starting plant material containing pectin processed using the method according to any one of claims 1 to 15, wherein the molecular weight of said pectin is up to 50% higher than the molecular weight of pectin obtained from extraction a similar but untreated pectin containing plant material. 26. Pectin according to claim 25, characterized in that the molecular weight of said pectin is 10-40% higher than the molecular weight of pectin obtained from extraction of a similar but untreated starting plant material containing pectin. 27. Pectin according to claim 26, characterized in that the molecular weight of said pectin is 15-30% higher than the molecular weight of pectin obtained from extraction of a similar but untreated starting plant material containing pectin. 28. Pectin obtained by extraction from a source of plant material containing pectin, processed using the method according to any one of claims 1 to 15, the ratio between the sensitivity to calcium of said pectin and the sensitivity to calcium of pectin extracted from a similar but untreated washing of the source plant material containing pectin is in the range of 0.90-1.40. 29. Pectin according to claim 28, characterized in that the ratio between the calcium sensitivity of said pectin and the calcium sensitivity of pectin extracted from a similar but untreated starting plant material containing pectin is in the range of 0.90-1.20. 30. Pectin according to clause 29, wherein the ratio between the calcium sensitivity of said pectin and the calcium sensitivity of pectin extracted from a similar but untreated plant material containing pectin is in the range of 0.90-1.10.